Throughout the customer journey, the employee-customer interaction drives customer responses. The COVID-19 pandemic has dramatically influenced shopping behavior with face masks playing a major role. This research investigates how consumer behavior has changed and how frontline employee (FLE) non-verbal (emotional facial expressions) and verbal cues (verbal expertise) influence customer responses dependent on whether FLEs wear a face mask or not. Semi-structured interviews among consumers, an open association study among students and an experimental study using Panel data were conducted. Findings of these online studies with German-speaking consumers show that face masks do not exclusively cause negative feelings and problems; they also reduce the perceived risk of a COVID-19 infection. Importantly, customers can correctly decode FLE smiling even when wearing face masks; however, the relevance of verbal expertise increases compared to FLE emotion displays. This state-of-the-art research during COVID-19 provides novel insights into dyadic service interactions for research and management.